51561967 has 4 divisors (see below), whose sum is σ = 51577056. Its totient is φ = 51546880.

The previous prime is 51561919. The next prime is 51561973. The reversal of 51561967 is 76916515.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 51561967 - 2¹⁵ = 51529199 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51561907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 303 + ... + 10159.

It is an arithmetic number, because the mean of its divisors is an integer number (12894264).

Almost surely, 2^51561967 is an apocalyptic number.

51561967 is a deficient number, since it is larger than the sum of its proper divisors (15089).

51561967 is an equidigital number, since it uses as much as digits as its factorization.

51561967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15088.

The product of its digits is 56700, while the sum is 40.

The square root of 51561967 is about 7180.6661947204. Note that the first 3 decimals coincide. The cubic root of 51561967 is about 372.2001057559.

The spelling of 51561967 in words is "fifty-one million, five hundred sixty-one thousand, nine hundred sixty-seven".